The Notebooks of Leonardo Da Vinci (57 page)

And in the arm you will put the motors of the fingers which open,
and these you will show separately in their demonstration. In the
second demonstration you will clothe these muscles with the
secondary motors of the fingers and so proceed by degrees to avoid
confusion. But first lay on the bones those muscles which lie close
to the said bones, without confusion of other muscles; and with
these you may put the nerves and veins which supply their
nourishment, after having first drawn the tree of veins and nerves
over the simple bones.

800.

Begin the anatomy at the head and finish at the sole of the foot.

801.

3 men complete, 3 with bones and nerves, 3 with the bones only. Here
we have 12 demonstrations of entire figures.

802.

When you have finished building up the man, you will make the statue
with all its superficial measurements.

[Footnote:
Cresciere l'omo
. The meaning of this expression appears
to be different here and in the passage C.A. 157a, 468a (see No.
526, Note 1. 2). Here it can hardly mean anything else than
modelling, since the sculptor forms the figure by degrees, by adding
wet clay and the figure consequently increases or grows.
Tu farai
la statua
would then mean, you must work out the figure in marble.
If this interpretation is the correct one, this passage would have
no right to find a place in the series on anatomical studies. I may
say that it was originally inserted in this connection under the
impression that
di cresciere
should be read
descrivere
.]

Plans for the representation of muscles by drawings (803-809).

803.

You must show all the motions of the bones with their joints to
follow the demonstration of the first three figures of the bones,
and this should be done in the first book.

804.

Remember that to be certain of the point of origin of any muscle,
you must pull the sinew from which the muscle springs in such a way
as to see that muscle move, and where it is attached to the
ligaments of the bones.

You will never get any thing but confusion in demonstrating the
muscles and their positions, origin, and termination, unless you
first make a demonstration of thin muscles after the manner of linen
threads; and thus you can represent them, one over another as nature
has placed them; and thus, too, you can name them according to the
limb they serve; for instance the motor of the point of the great
toe, of its middle bone, of its first bone, &c. And when you have
the knowledge you will draw, by the side of this, the true form and
size and position of each muscle. But remember to give the threads
which explain the situation of the muscles in the position which
corresponds to the central line of each muscle; and so these threads
will demonstrate the form of the leg and their distance in a plain
and clear manner.

I have removed the skin from a man who was so shrunk by illness that
the muscles were worn down and remained in a state like thin
membrane, in such a way that the sinews instead of merging in
muscles ended in wide membrane; and where the bones were covered by
the skin they had very little over their natural size.

[Footnote: The photograph No. 41 of Grosvenor Gallery Publications:
a drawing of the muscles of the foot, includes a complete facsimile
of the text of this passage.]

805.

Which nerve causes the motion of the eye so that the motion of one
eye moves the other?

Of frowning the brows, of raising the brows, of lowering the
brows,—of closing the eyes, of opening the eyes,—of raising the
nostrils, of opening the lips, with the teeth shut, of pouting with
the lips, of smiling, of astonishment.—

Describe the beginning of man when it is caused in the womb and why
an eight months child does not live. What sneezing is. What yawning
is. Falling sickness, spasms, paralysis, shivering with cold,
sweating, fatigue, hunger, sleepiness, thirst, lust.

Of the nerve which is the cause of movement from the shoulder to the
elbow, of the movement from the elbow to the hand, from the joint of
the hand to the springing of the fingers. From the springing of the
fingers to the middle joints, and from the middle joints to the
last.

Of the nerve which causes the movement of the thigh, and from the
knee to the foot, and from the joint of the foot to the toes, and
then to the middle of the toes and of the rotary motion of the leg.

806.

Which nerves or sinews of the hand are those which close and part
the fingers and toes latteraly?

807.

Remove by degrees all the parts of the front of a man in making your
dissection, till you come to the bones. Description of the parts of
the bust and of their motions.

808.

Give the anatomy of the leg up to the hip, in all views and in every
action and in every state; veins, arteries, nerves, sinews and
muscles, skin and bones; then the bones in sections to show the
thickness of the bones.

[Footnote: A straightened leg in profile is sketched by the side of
this text.]

On corpulency and leanness (809-811).

809.

Make the rule and give the measurement of each muscle, and give the
reasons of all their functions, and in which way they work and what
makes them work &c.

[4] First draw the spine of the back; then clothe it by degrees, one
after the other, with each of its muscles and put in the nerves and
arteries and veins to each muscle by itself; and besides these note
the vertebrae to which they are attached; which of the intestines
come in contact with them; and which bones and other organs &c.

The most prominent parts of lean people are most prominent in the
muscular, and equally so in fat persons. But concerning the
difference in the forms of the muscles in fat persons as compared
with muscular persons, it shall be described below.

[Footnote: The two drawings given on Pl. CVIII no. 1 come between
lines 3 and 4. A good and very early copy of this drawing without
the written text exists in the collection of drawings belonging to
Christ's College Oxford, where it is attributed to Leonardo.]

810.

Describe which muscles disappear in growing fat, and which become
visible in growing lean.

And observe that that part which on the surface of a fat person is
most concave, when he grows lean becomes more prominent.

Where the muscles separate one from another you must give profiles
and where they coalesce …

811.

Which is the part in man, which, as he grows fatter, never gains
flesh?

Or what part which as a man grows lean never falls away with a too
perceptible diminution? And among the parts which grow fat which is
that which grows fattest?

Among those which grow lean which is that which grows leanest?

In very strong men which are the muscles which are thickest and most
prominent?

In your anatomy you must represent all the stages of the limbs from
man's creation to his death, and then till the death of the bone;
and which part of him is first decayed and which is preserved the
longest.

And in the same way of extreme leanness and extreme fatness.

The divisions of the head (812. 813).

812.

There are eleven elementary tissues:— Cartilage, bones, nerves,
veins, arteries, fascia, ligament and sinews, skin, muscle and fat.

The divisions of the head are 10, viz. 5 external and 5 internal,
the external are the hair, skin, muscle, fascia and the skull; the
internal are the dura mater, the pia mater, [which enclose] the
brain. The pia mater and the dura mater come again underneath and
enclose the brain; then the rete mirabile, and the occipital bone,
which supports the brain from which the nerves spring.

813.

a
. hair

n
. skin

c
. muscle

m
. fascia

o
. skull
i.e.
bone

b
. dura mater

d
. pia mater

f
. brain

r
. pia mater, below

t
. dura mater

l
. rete mirablile

s
. the occipitul bone.

[Footnote: See Pl. CVIII, No. 3.]

Physiological problems (814. 815).

814.

Of the cause of breathing, of the cause of the motion of the heart,
of the cause of vomiting, of the cause of the descent of food from
the stomach, of the cause of emptying the intestines.

Of the cause of the movement of the superfluous matter through the
intestines.

Of the cause of swallowing, of the cause of coughing, of the cause
of yawning, of the cause of sneezing, of the cause of limbs getting
asleep.

Of the cause of losing sensibility in any limb.

Of the cause of tickling.

Of the cause of lust and other appetites of the body, of the cause
of urine and also of all the natural excretions of the body.

[Footnote: By the side of this text stands the pen and ink drawing
reproduced on Pl. CVIII, No. 4; a skull with indications of the
veins in the fleshy covering.]

815.

The tears come from the heart and not from the brain.

Define all the parts, of which the body is composed, beginning with
the skin with its outer cuticle which is often chapped by the
influence of the sun.

The divisions of the animal kingdom (816. 817).

816.

Man
. The description of man, which includes that of such creatures
as are of almost the same species, as Apes, Monkeys and the like,
which are many,

The Lion
and its kindred, as Panthers. [Footnote 3:
Leonza
—wild
cat? "
Secondo alcuni, lo stesso che Leonessa; e secondo altri con
piu certezza, lo stesso che Pantera
" FANFANI,
Vocabolario
page
858.] Wildcats (?) Tigers, Leopards, Wolfs, Lynxes, Spanish cats,
common cats and the like.

The Horse
and its kindred, as Mule, Ass and the like, with incisor
teeth above and below.

The Bull
and its allies with horns and without upper incisors as
the Buffalo, Stag Fallow Deer, Wild Goat, Swine, Goat, wild Goats
Muskdeers, Chamois, Giraffe.

817.

Describe the various forms of the intestines of the human species,
of apes and such like. Then, in what way the leonine species differ,
and then the bovine, and finally birds; and arrange this description
after the manner of a disquisition.

Miscellaneous notes on the study of Zoology (818-821).

818.

Procure the placenta of a calf when it is born and observe the form
of the cotyledons, if their cotyledons are male or female.

819.

Describe the tongue of the woodpecker and the jaw of the crocodile.

820.

Of the flight of the 4th kind of butterflies that consume winged
ants. Of the three principal positions of the wings of birds in
downward flight.

[Footnote: A passing allusion is all I can here permit myself to
Leonardo's elaborate researches into the flight of birds. Compare
the observations on this subject in the Introduction to section
XVIII and in the Bibliography of Manuscripts at the end of the
work.]

821.

Of the way in which the tail of a fish acts in propelling the fish;
as in the eel, snake and leech.

[Footnote: A sketch of a fish, swimming upwards is in the original,
inserted above this text.—Compare No. 1114.]

Comparative study of the structure of bones and of the action of
muscles (822-826).

822.

Then I will discourse of the hands of each animal to show in what
they vary; as in the bear, which has the ligatures of the sinews of
the toes joined above the instep.

823.

A second demonstration inserted between anatomy and [the treatise
on] the living being.

You will represent here for a comparison, the legs of a frog, which
have a great resemblance to the legs of man, both in the bones and
in the muscles. Then, in continuation, the hind legs of the hare,
which are very muscular, with strong active muscles, because they
are not encumbered with fat.

[Footnote: This text is written by the side of a drawing in black
chalk of a nude male figure, but there is no connection between the
sketch and the text.]

824.

Here I make a note to demonstrate the difference there is between
man and the horse and in the same way with other animals. And first
I will begin with the bones, and then will go on to all the muscles
which spring from the bones without tendons and end in them in the
same way, and then go on to those which start with a single tendon
at one end.

[Footnote: See Pl. CVIII, No. 2.]

825.

Note on the bendings of joints and in what way the flesh grows upon
them in their flexions or extensions; and of this most important
study write a separate treatise: in the description of the movements
of animals with four feet; among which is man, who likewise in his
infancy crawls on all fours.

826.

The walking of man is always after the universal manner of walking
in animals with 4 legs, inasmuch as just as they move their feet
crosswise after the manner of a horse in trotting, so man moves his
4 limbs crosswise; that is, if he puts forward his right foot in
walking he puts forward, with it, his left arm and vice versa,
invariably.

Comparative study of the organs of sense in men and animals.

827.

I have found that in the composition of the human body as compared
with the bodies of animals the organs of sense are duller and
coarser. Thus it is composed of less ingenious instruments, and of
spaces less capacious for receiving the faculties of sense. I have
seen in the Lion tribe that the sense of smell is connected with
part of the substance of the brain which comes down the nostrils,
which form a spacious receptacle for the sense of smell, which
enters by a great number of cartilaginous vesicles with several
passages leading up to where the brain, as before said, comes down.